Abstract: In a solar electric supply system in which an electrical load is supplied with current produced by a solar array formed of multiple solar panels, each solar panel is individually selected and tested to ensure proper performance by varying the duty cycle of an associated variable transconductance device connected between such solar panel and the electrical load. The method determines the respective solar panel's open circuit voltage, its full-load current and obtains various output voltage and current values responsive to different duty cycles, whereby the maximum power point for the solar panel may be determined.

Abstract: A system for supplying d.c. power to an electrical load, in which such load includes a rechargeable battery, is characterized by a plurality of power sources connected in common to the electrical load, wherein the current generated by the multiple power sources is combined to supply such electrical load. Each of the power sources includes a solar panel and a controlled variable transconductance device, such as a Buck converter, connected in electrical series circuit. A digital processor, including a stored program, coupled to the control inputs of the variable transconductance devices, selectively individually sets the duty cycle of each transconductance device under control of a stored program, whereby the electrical power supplied by said power sources to said electrical load is individually controlled by the digital processor.